CN111208640A

CN111208640A - Eyepiece optical system

Info

Publication number: CN111208640A
Application number: CN202010083639.6A
Authority: CN
Inventors: 马修·博恩
Original assignee: Yujing Optoelectronics Xiamen Co Ltd
Current assignee: Yujing Optoelectronics Xiamen Co Ltd; Genius Electronic Optical Xiamen Co Ltd
Priority date: 2016-09-19
Filing date: 2017-03-02
Publication date: 2020-05-29
Anticipated expiration: 2037-03-02
Also published as: TWI664448B; TW202024707A; US20200249474A1; TWI692650B; US20220342209A1; TWI754465B; US20180081151A1; US10606070B2; TW202120991A; TWI715469B; US11366314B2; TW201935087A; TW201831958A; CN111208640B

Abstract

The invention discloses an eyepiece optical system which is used for imaging light rays entering eyes of an observer from a display picture through the eyepiece optical system. The direction toward the eyes is the eye side, and the direction toward the display screen is the display side. The eyepiece optical system comprises a first lens, a second lens and a third lens in sequence from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface. The second lens element has a positive refractive index, and the display side surface of the second lens element has a concave surface portion located in a region near the optical axis.

Description

Eyepiece optical system

The patent application of the invention is divisional application. The original application number is 201710121215.2, the application date is 2017, 03 and 02, and the invention name is: an eyepiece optical system.

Technical Field

The invention relates to the field of optical systems, in particular to an eyepiece optical system.

Background

Virtual Reality (VR) is a Virtual world which is created by using computer technology to simulate, and provides sense simulation about vision, hearing and the like for a user, so that the user feels the user to experience the Virtual world. The existing VR device is mainly used for visual experience. The parallax of human eyes is simulated by the divided pictures which are slightly different from the two visual angles of the left and right eyes, so as to achieve the stereoscopic vision. In order to reduce the size of the virtual reality device and make the user obtain the enlarged visual sensation through a smaller display screen, an eyepiece optical system with an enlarging function has been one of the subjects of VR research and development.

The half-eye viewing angle of the conventional eyepiece optical system is small, so that the observer feels that the vision is narrow, the resolution is low, and the aberration compensation is performed before the display picture is serious, so how to increase the half-eye viewing angle and enhance the imaging quality is a problem that needs to be improved.

Disclosure of Invention

The invention provides an eyepiece optical system which can still keep good optical imaging quality and large half-eye visual angle under the condition of shortening the length of the system.

The embodiment of the invention provides an eyepiece optical system which is used for imaging the eyes of an observer by imaging light rays entering from a display picture through the eyepiece optical system. The direction toward the eyes is the eye side, and the direction toward the display screen is the display side. The eyepiece optical system comprises a first lens, a second lens and a third lens in sequence from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface.

In an embodiment of the invention, the first lens element has a refractive index. The second lens element has a positive refractive index, and the display side surface of the second lens element has a concave surface portion located in a region near the optical axis. At least one of the object side surface and the display side surface of the third lens is an aspheric surface.

In an embodiment of the invention, the first lens element has a refractive index. The eye side surface of the second lens is provided with a convex surface part which is positioned in the area near the optical axis. The display side surface of the second lens is provided with a concave surface part positioned in the area near the optical axis. The third lens element has a negative refractive index, and at least one of the eye-side surface and the display-side surface of the third lens element is aspheric.

In an embodiment of the invention, the first lens element has a refractive index. The eye side surface of the second lens is provided with a convex surface part positioned in the area near the optical axis, and the display side surface of the second lens is provided with a concave surface part positioned in the area near the optical axis. The eye side surface of the third lens is provided with a concave surface part positioned in the area nearby the circumference, and at least one of the eye side surface and the display side surface of the third lens is an aspheric surface.

In an embodiment of the present invention, the eyepiece optical system conforms to: 2.5 ≦ 250mm/G3D ≦ 25, where G3D is a distance between the third lens and the display screen on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.5 ≦ (T1+ G12)/T2 ≦ 4.5, where T1 is a thickness of the first lens on the optical axis, G12 is an air gap from the first lens to the second lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.5 ≦ T1/T2 ≦ 4, where T1 is a thickness of the first lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 2.5 ≦ ER/T3 ≦ 5, where ER is the distance of the pupil of the eye of the observer to the first lens on the optical axis, and T3 is the thickness of the third lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.69 ≦ (ER + G12+ T3)/T1 ≦ 2.09, where ER is a distance of the pupil of the eye of the observer to the first lens on the optical axis, G12 is an air gap of the first lens to the second lens on the optical axis, T3 is a thickness of the third lens on the optical axis, and T1 is a thickness of the first lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.38 ≦ (ER + G12+ T3)/G3D ≦ 1.02, where ER is a distance of the pupil of the eye of the observer to the first lens on the optical axis, G12 is an air gap of the first lens to the second lens on the optical axis, T3 is a thickness of the third lens on the optical axis, and G3D is a distance of the third lens to the display screen on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 1.3 ≦ DLD/G3D ≦ 5, where DLD is the diagonal length of the display corresponding to the single pupil of the viewer, and G3D is the distance from the third lens to the display on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 2.5 ≦ TTL/(T2+ T3) ≦ 9, where TTL is a distance between the object side surface of the first lens and the display screen on the optical axis, T2 is a thickness of the second lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 2.0 ≦ D2/T2, where D2 is the optical effective diameter of the eye-side surface of the second lens, and T2 is the thickness of the second lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 3.5 ≦ EFL/ER ≦ 4.5, where EFL is a system focal length of the eyepiece optical system and ER is a distance of a pupil of the eye of the observer to the first lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.79 ≦ (ER + G12+ T3)/T2 ≦ 3.25, where ER is a distance of the pupil of the eye of the observer to the first lens on the optical axis, G12 is an air gap of the first lens to the second lens on the optical axis, T3 is a thickness of the third lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 1.27 ≦ (ER + G12+ G3D)/T1 ≦ 7.19, where ER is a distance on the optical axis from the pupil of the eye of the observer to the first lens, G12 is an air gap on the optical axis from the first lens to the second lens, G3D is a distance on the optical axis from the third lens to the display, and T1 is a thickness of the first lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: TTL/(G23+ T3) ≦ 23, where TTL is a distance between the object side surface of the first lens and the display screen on the optical axis, G23 is an air gap between the second lens and the third lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 6.0 ≦ D3/T3, where D3 is the optical effective diameter of the eye-side surface of the third lens, and T3 is the thickness of the third lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 20 ≦ DLD/EPSD ≦ 36, where DLD is the diagonal length of the display corresponding to the single pupil of the viewer and EPSD is the half diameter of the single pupil of the viewer.

In an embodiment of the present invention, the eyepiece optical system conforms to: 0.99 ≦ (ER + G12+ T3)/G23 ≦ 16.16, where ER is a distance of the pupil of the eye of the observer to the first lens on the optical axis, G12 is an air gap of the first lens to the second lens on the optical axis, T3 is a thickness of the third lens on the optical axis, and G23 is an air gap of the second lens to the third lens on the optical axis.

In an embodiment of the present invention, the eyepiece optical system conforms to: 1.71 ≦ (ER + G12+ G3D)/T2 ≦ 11.19, where ER is a distance on the optical axis from the pupil of the eye of the observer to the first lens, G12 is an air gap on the optical axis from the first lens to the second lens, G3D is a distance on the optical axis from the third lens to the display, and T2 is a thickness on the optical axis of the second lens.

In an embodiment of the invention, the first lens element has a positive refractive index. The eye side surface of the second lens is provided with a convex surface part positioned in the area near the optical axis, and the display side surface of the second lens is provided with a convex surface part positioned in the area near the optical axis. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis.

In an embodiment of the invention, the first lens element has a positive refractive index. The eye side surface of the second lens is provided with a convex surface part positioned in a peripheral nearby area, and the display side surface of the second lens is provided with a convex surface part positioned in an optical axis nearby area. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis.

In an embodiment of the invention, the display side surface of the second lens element has a convex surface portion located in a region near the optical axis. The third lens element has a negative refractive index. The eye side surface of the third lens is provided with a convex surface part positioned in an area near the optical axis and a convex surface part positioned in an area near the circumference.

In an embodiment of the invention, the display side surface of the second lens element has a convex surface portion located in a region near the optical axis. The eye side surface of the third lens is provided with a convex surface part positioned in an area near the optical axis and a convex surface part positioned in an area near the circumference. The display side surface of the third lens is provided with a concave surface part positioned in the area near the optical axis.

In an embodiment of the invention, the display side surface of the second lens element has a convex surface portion located in a region near the optical axis. The eye side surface of the third lens is provided with a convex surface part positioned in an area near the optical axis and a convex surface part positioned in an area near the circumference. The display side surface of the third lens is provided with a concave surface part located in the area near the circumference.

In an embodiment of the invention, the second lens element has a positive refractive index. The eye side surface of the second lens is provided with a convex surface part which is positioned in the area near the optical axis. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis. The display side surface of the third lens is provided with a concave surface part located in the area near the circumference.

In an embodiment of the invention, the eye-side surface of the second lens element has a convex surface portion located in a region near the optical axis. The display side surface of the second lens is provided with a convex surface part positioned in the area near the optical axis. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis. The display side surface of the third lens is provided with a concave surface part located in the area near the circumference.

In an embodiment of the invention, the eye-side surface of the second lens element has a convex surface portion located in a region near the optical axis. The display side surface of the second lens is provided with a convex surface part positioned in the area near the circumference. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis. The display side surface of the third lens is provided with a concave surface part located in the area near the circumference.

In an embodiment of the invention, the eye-side surface of the second lens element has a convex surface portion located in a region near the optical axis. The third lens element has a negative refractive index. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis. The display side surface of the third lens is provided with a concave surface part located in the area near the circumference.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The display side surface of the third lens is provided with a convex surface part positioned in the area near the circumference.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The eye side surface of the second lens has a concave surface portion located in a region near the circumference.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The eye side surface of the third lens is provided with a convex surface part which is positioned in the area near the optical axis.

In an embodiment of the invention, the eye-side surface of the first lens element has a concave surface portion located in a region near the optical axis and a convex surface portion located in a region near the circumference.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The second lens element has a negative refractive index.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The eye side surface of the second lens is provided with a concave surface part which is positioned in the area near the optical axis.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The third lens element has positive refractive index.

In an embodiment of the invention, the eye side surface of the first lens has a concave surface portion located in a region near the optical axis. The eye-side surface of the third lens has a convex surface portion located in a region near the circumference.

In an embodiment of the invention, the eye-side surface of the second lens element has a convex surface portion located in a region near the optical axis. The display side surface of the second lens is provided with a concave surface part positioned in the area near the optical axis. The eye side surface of the third lens is provided with a concave surface part located in the area near the optical axis.

In an embodiment of the invention, the eye-side surface of the second lens element has a convex surface portion located in a region near the optical axis. The eye side surface of the third lens is provided with a concave surface part located in the area near the optical axis. The display side surface of the third lens is provided with a convex surface part positioned in the area near the optical axis.

Based on the above, the eyepiece optical system of the embodiment of the present invention has the following beneficial effects: by the design and arrangement of the surface shape and the refractive index of the lens and the design of the optical parameters, the eyepiece optical system still has the optical performance of effectively overcoming the aberration under the condition of shortening the system length, provides good imaging quality and has a large visual angle (apparent field of view).

Drawings

Fig. 1 is a schematic diagram illustrating an eyepiece optical system.

FIG. 2 is a schematic diagram illustrating a face structure of a lens.

Fig. 3 is a schematic diagram illustrating a surface type concave-convex structure and a light focus of a lens.

Fig. 4 is a diagram illustrating a surface structure of a lens according to an example.

Fig. 5 is a schematic diagram illustrating a surface structure of a lens according to a second example.

Fig. 6 is a schematic diagram illustrating a surface structure of a lens according to a third example.

Fig. 7 is a schematic view of an eyepiece optical system of a first embodiment of the present invention.

Fig. 8A to 8D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the first embodiment.

Fig. 9 is a detailed optical data table diagram of the eyepiece optical system of the first embodiment of the present invention.

FIG. 10 is a table of aspheric parameters of the eyepiece optical system according to the first embodiment of the present invention.

Fig. 11 is a schematic view of an eyepiece optical system of a second embodiment of the present invention.

Fig. 12A to 12D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the second embodiment.

Fig. 13 is a detailed optical data table diagram of the eyepiece optical system of the second embodiment of the present invention.

FIG. 14 is a table of aspheric parameters of an eyepiece optical system according to a second embodiment of the present invention.

Fig. 15 is a schematic view of an eyepiece optical system of a third embodiment of the present invention.

Fig. 16A to 16D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the third embodiment.

Fig. 17 is a detailed optical data table diagram of the eyepiece optical system according to the third embodiment of the present invention.

FIG. 18 is a table of aspheric parameters of an eyepiece optical system according to a third embodiment of the present invention.

Fig. 19 is a schematic view of an eyepiece optical system of a fourth embodiment of the present invention.

Fig. 20A to 20D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the fourth embodiment.

Fig. 21 is a detailed optical data table diagram of the eyepiece optical system according to the fourth embodiment of the present invention.

Fig. 22 is a table of aspheric parameters of an eyepiece optical system according to a fourth embodiment of the present invention.

Fig. 23 is a schematic view of an eyepiece optical system of a fifth embodiment of the present invention.

Fig. 24A to 24D are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the fifth embodiment.

Fig. 25 is a detailed optical data table diagram of the eyepiece optical system according to the fifth embodiment of the present invention.

Fig. 26 is an aspherical parameter table diagram of an eyepiece optical system according to a fifth embodiment of the present invention.

Fig. 27 is a schematic view of an eyepiece optical system of a sixth embodiment of the present invention.

Fig. 28A to 28D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the sixth embodiment.

Fig. 29 is a detailed optical data table diagram of the eyepiece optical system according to the sixth embodiment of the present invention.

Fig. 30 is an aspherical parameter table diagram of an eyepiece optical system according to a sixth embodiment of the present invention.

Fig. 31 is a schematic view of an eyepiece optical system of a seventh embodiment of the present invention.

Fig. 32A to 32D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the seventh embodiment.

Fig. 33 is a detailed optical data table diagram of the eyepiece optical system according to the seventh embodiment of the present invention.

Fig. 34 is an aspherical parameter table diagram of an eyepiece optical system according to a seventh embodiment of the present invention.

Fig. 35 is a schematic view of an eyepiece optical system of an eighth embodiment of the present invention.

Fig. 36A to 36D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the eighth embodiment.

Fig. 37 is a detailed optical data table diagram of the eyepiece optical system according to the eighth embodiment of the present invention.

Fig. 38 is an aspherical parameter table diagram of an eyepiece optical system according to an eighth embodiment of the present invention.

Fig. 39 is a schematic view of an eyepiece optical system of a ninth embodiment of the present invention.

Fig. 40A to 40D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the ninth embodiment.

Fig. 41 is a detailed optical data table diagram of the eyepiece optical system according to the ninth embodiment of the present invention.

Fig. 42 is an aspherical parameter table diagram of an eyepiece optical system according to a ninth embodiment of the present invention.

Fig. 43 is a table of values of important parameters and their relational expressions of the eyepiece optical systems according to the first to fifth embodiments of the present invention.

Fig. 44 is a table of values of important parameters and their relational expressions of the eyepiece optical systems according to the first to fifth embodiments of the present invention.

Fig. 45 is a table of values of important parameters and their relations of the eyepiece optical systems according to the sixth to ninth embodiments of the present invention.

Fig. 46 is a table of values of important parameters and their relations of the eyepiece optical systems according to the sixth to ninth embodiments of the present invention.

Detailed Description

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the accompanying drawings. The drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references in mind, one skilled in the art will understand that other embodiments are possible and that the advantages of the invention are realized. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

Symbolic illustration in the drawings:

10. v100: an eyepiece optical system; 100. v50: displaying a picture; 2: a pupil; 3: a first lens; 31. 41, 51: the side of the eye; 311. 313, 321, 323, 411, 413, 421, 423, 511, 513, 521, 523: a convex surface portion; 312. 314, 412, 414, 422, 424, 512, 514, 522, 524: a concave surface portion; 32. 42, 52: a display side; 4: a second lens; 425. 426: a planar portion; 5: a third lens; a: an optical axis vicinity region; c: a circumferential vicinity; DLD: the diagonal length of the display screen corresponding to a single pupil of the observer; e: an extension portion; EPD: an exit pupil diameter; i: an optical axis; lc: a chief ray; lm: an edge ray; m, R: point; v60: an eye; VD: distance of photopic vision; VI: imaging light; VV: amplifying the virtual image; ω: half eye view.

Generally, the light of the eyepiece optical system V100 is an imaging light VI emitted from the display screen V50, enters the eye V60 through the eyepiece optical system V100, is focused on the retina of the eye V60 and generates an enlarged virtual image VV at the photopic distance VD, as shown in fig. 1. The criterion for the optical specification in the present application is to assume that the light direction reverse tracking (reverse tracking) is a parallel imaging light from the eye side to the display screen through the eyepiece optical system for focusing and imaging.

In the present specification, the term "a lens having positive refractive index (or negative refractive index)" means that the refractive index of the lens on the optical axis calculated by the Gaussian optics theory is positive (or negative). The display side and the target side are defined as a range through which imaging light passes, wherein the imaging light includes a chief ray (chief ray) Lc and a marginal ray (marginal ray) Lm, as shown in fig. 2, I is an optical axis and the lens is radially symmetrical to each other with the optical axis I as a symmetry axis, a region on the optical axis through which light passes is an area a near the optical axis, and a region through which marginal light passes is an area C near the circumference. More specifically, the method of determining the surface shape, the area near the optical axis, the area near the circumference, or the ranges of a plurality of areas is as follows:

1. fig. 2 is a cross-sectional view of a lens in a radial direction. When the area is judged to be within the range, a central point is defined as an intersection point of the lens surface and the optical axis, and a conversion point is a point on the lens surface, and a tangent line passing through the point is vertical to the optical axis. If there are plural conversion points outward in the radial direction, the first conversion point and the second conversion point are in sequence, and the conversion point farthest from the optical axis in the radial direction on the effective radius is the Nth conversion point. The range between the central point and the first conversion point is an area near the optical axis, the area radially outward of the Nth conversion point is an area near the circumference, and different areas can be distinguished according to the conversion points in the middle. Further, the effective radius is the perpendicular distance from the intersection of the marginal ray Lm with the lens surface to the optical axis I.

2. As shown in fig. 3, the shape irregularity of the region is determined on the display side or the eye side by the intersection of the light beam (or the light beam extension line) passing through the region in parallel with the optical axis (light beam focus determination method). For example, when the light passes through the region, the light is focused toward the display side, and the focal point of the light axis is located at the display side, such as the point R in fig. 3, the region is a convex surface. Conversely, if the light beam passes through the certain region, the light beam diverges such that the extension line of the light beam and the focal point of the optical axis are on the object side, e.g., point M in fig. 3, the region is a concave surface portion, so that a convex surface portion is formed between the central point and the first transition point, and the region radially outward of the first transition point is a concave surface portion; as can be seen from fig. 3, the transition point is the boundary point between the convex surface portion and the concave surface portion, so that the area defined by the transition point and the area adjacent to the radially inner side of the area have different surface shapes with the transition point as the boundary. In addition, the determination of the surface shape in the region near the optical axis can be performed by a method of determination by a person ordinarily skilled in the art, and the irregularities can be determined by positive or negative R values (which refer to the radius of curvature of the paraxial region, and which refer to R values in a lens database (lens data) in optical software). For the eye side, when the R value is positive, the eye side is judged to be a convex side, and when the R value is negative, the eye side is judged to be a concave side; in the case of the display side surface, when the R value is positive, it is determined as a concave surface portion, and when the R value is negative, it is determined as a convex surface portion, and the unevenness determined by this method is determined in the same manner as the light focus determination.

3. If there is no transition point on the lens surface, the area near the optical axis is defined as 0 to 50% of the effective radius, and the area near the circumference is defined as 50 to 100% of the effective radius.

The lens of example one of fig. 4 shows that the side surface has only the first transition point on the effective radius, and the first zone is the area near the optical axis and the second zone is the area near the circumference. The R value of the display side of the lens is positive, so that the area near the optical axis is judged to have a concave surface part; the surface shape of the circumferential vicinity is different from the inner side area immediately radially adjacent to the circumferential vicinity. That is, the surface shapes of the area near the circumference and the area near the optical axis are different; the peripheral region has a convex portion.

The lens eye-side surface of the second example of fig. 5 has first and second transition points on the effective radius, and the first region is the region near the optical axis and the third region is the region near the circumference. The R value of the lens eye side surface is positive, so that the area near the optical axis is judged to be a convex surface part; the region (second region) between the first transition point and the second transition point has a concave surface portion, and the region (third region) near the circumference has a convex surface portion.

The lens eye-side surface of example three of fig. 6 has no transition point on the effective radius, and the effective radius is 0% to 50% of the area near the optical axis and 50% to 100% of the area near the circumference. The optical axis vicinity area has a convex surface part due to the positive R value; there is no transition point between the area near the circumference and the area near the optical axis, so the area near the circumference has a convex surface portion.

Fig. 7 is a schematic view of an eyepiece optical system according to a first embodiment of the present invention, and fig. 8A to 8D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the first embodiment. Referring to fig. 7, the eyepiece optical system 10 of the first embodiment of the invention is used for imaging the eye of the observer through the eyepiece optical system 10 and the pupil 2 of the eye of the observer from the display screen 100, where the direction toward the eye is the eye side and the direction toward the display screen 100 is the display side. The eyepiece optical system 10 includes a first lens 3, a second lens 4, and a third lens 5 in this order along an optical axis I of the eyepiece optical system 10 from the object side to the display side. When light emitted from the display screen 100 enters the eyepiece optical system 10, and sequentially passes through the third lens 5, the second lens 4 and the first lens 3, the light enters the eyes of the observer through the pupil 2, and an image is formed on the retinas of the eyes.

The first lens 3, the second lens 4 and the third lens 5 each have a

eye side surface

31, 41, 51 facing the eye side and passing the image light therethrough and a

display side surface

32, 42, 52 facing the display side and passing the image light therethrough. In order to satisfy the requirement of light weight of the product, the first lens element 3, the second lens element 4 and the third lens element 5 all have refractive indexes, and the first lens element 3, the second lens element 4 and the third lens element 5 are all made of plastic materials, but the materials of the first lens element 3, the second lens element 4 and the third lens element 5 are not limited thereto.

The first lens element 3 has a positive refractive index. The object side surface 31 of the first lens element 3 is convex and has a convex portion 311 located in the vicinity of the optical axis I and a convex portion 313 located in the vicinity of the circumference. The display side surface 32 of the first lens element 3 is convex, and has a convex portion 321 located in the vicinity of the optical axis I and a convex portion 323 located in the vicinity of the circumference.

The second lens element 4 has a positive refractive index. The eye side surface 41 of the second lens element 4 is a convex surface, and has a convex surface 411 located in the vicinity of the optical axis I and a convex surface 413 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 is a convex surface, and has a convex surface 421 located in the vicinity of the optical axis I and a convex surface 423 located in the vicinity of the circumference.

The third lens element 5 has a negative refractive index. The eye-side surface 51 of the third lens element 5 is convex, and has a convex portion 511 located in the vicinity of the optical axis I and a convex portion 513 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is concave and has a concave portion 522 located in the vicinity of the optical axis I and a concave portion 524 located in the vicinity of the circumference.

In addition, in the present embodiment, only the lenses have refractive indexes, and the eyepiece optical system 10 has only three lenses with refractive indexes.

Fig. 1, 43 and 44 show relationships among important parameters in the eyepiece optical system 10 according to the first embodiment.

Wherein the content of the first and second substances,

EPD is the exit pupil diameter (exit pupil diameter) of the eyepiece optical system 10, corresponding to the diameter of the viewer's pupil 2, which is about 3mm during the day and up to about 7mm at night, as shown in fig. 1;

EPSD is the half diameter of the observer's pupil 2 (semidiameter);

er (eye relief) is the exit pupil distance, i.e. the distance of the observer's pupil 2 to the first lens 3 on the optical axis I;

ω is half-eye view (half-field of view), i.e., half the viewing angle of the viewer, as shown in FIG. 1;

t1 is the thickness of the first lens 3 on the optical axis I;

t2 is the thickness of the second lens 4 on the optical axis I;

t3 is the thickness of the third lens 5 on the optical axis I;

g12 is the distance on the optical axis I from the display side surface 32 of the first lens 3 to the eye side surface 41 of the second lens 4, i.e. the air gap on the optical axis I from the first lens 3 to the second lens 4;

g23 is the distance on the optical axis I from the display side surface 42 of the second lens 4 to the eye side surface 51 of the third lens 5, i.e. the air gap on the optical axis I from the second lens 4 to the third lens 5;

G3D is the distance between the display side 52 of the third lens 5 and the display screen 100 on the optical axis I, i.e. the air gap between the third lens 5 and the display screen 100 on the optical axis I;

DLD is the diagonal length of the display screen 100 corresponding to a single pupil 2 of the observer, as shown in FIG. 1;

the distance of visibility (distance of visibility) is the closest distance at which the eyes can focus clearly, and is usually 250mm (millimeter) for young people, such as the distance of visibility VD shown in fig. 1;

ALT is the sum of the thicknesses of the first lens 3, the second lens 4, and the third lens 5 on the optical axis I, i.e., the sum of T1 and T2;

gaa is the sum of two air gaps on the optical axis I of the first lens 3 to the third lens 5, i.e., the sum of G12 and G23;

TTL is the distance from the eye side surface 31 of the first lens element 3 to the display 100 on the optical axis I;

TL is the distance on the optical axis I from the eye side surface 31 of the first lens 3 to the display side surface 52 of the third lens 5;

SL is the system length, i.e. the distance from the pupil 2 of the observer to the display screen 100 on the optical axis I; and

the EFL is the system focal length of the eyepiece optical system 10.

In addition, redefining:

f1 is the focal length of the first lens 3;

f2 is the focal length of the second lens 4;

f3 is the focal length of the third lens 5;

n1 is the refractive index of the first lens 3;

n2 is the refractive index of the second lens 4;

n3 is the refractive index of the third lens 5;

ν 1 is Abbe number (Abbe number) of the first lens 3, which can also be referred to as Abbe number;

ν 2 is an abbe number of the second lens 4;

ν 3 is an abbe number of the third lens 5;

d1 is the optical effective diameter (a diameter of a clear aperture) of the object side surface 31 of the first lens 3;

d2 is the optical effective diameter of the eye-side surface 41 of the second lens 4; and

d3 is the optical effective diameter of the ocular surface 51 of the third lens 5.

Other detailed optical data of the first embodiment are shown in fig. 9, and the overall system focal length (EFL) of the eyepiece optical system 10 of the first embodiment is 48.594mm, the half-angle of view (ω) is 40.000 °, the TTL is 56.100mm, and the aperture value (f-number, Fno) is 9.626. Specifically, the "aperture value" in the present specification is an aperture value calculated based on the principle of reversibility of light, with the object side as the object side, the display side as the image side, and the pupil of the observer as the entrance pupil. Furthermore, 0.5 times DLD was 40.459 mm. The effective radius in fig. 9 is a half of the optical effective radius.

In the present embodiment, the eye-side surface 31 and the display-side surface 32 of the first lens 3 and the eye-side surface 51 and the display-side surface 52 of the third lens 5 are all aspheric, and the eye-side surface 41 and the display-side surface 42 of the second lens 4 are spherical. These aspherical surfaces are defined by the following formula:

wherein:

y: the distance between a point on the aspheric curve and the optical axis I;

z: the depth of the aspheric surface (the vertical distance between the point on the aspheric surface that is Y from the optical axis I and the tangent plane tangent to the vertex on the optical axis I);

r is the curvature radius of the lens surface at the position close to the optical axis I;

k: cone constant (conc constant);

a_i: the ith order aspheric coefficients.

The aspheric coefficients of the object side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 in the formula (1) are shown in FIG. 10. In fig. 10, the field number 31 indicates that it is an aspheric coefficient of the eye side surface 31 of the first lens 3, and so on. In fig. 10, the aspheric coefficients of the eye side surface 41 and the display side surface 42 are all zero, which means that the eye side surface 41 and the display side surface 42 are spherical.

Referring to fig. 8A to 8D, fig. 8A to 8D are aberration diagrams of the eyepiece optical system 10 of the first embodiment, and are aberration diagrams obtained by assuming that the light direction is reversely traced and a parallel imaging light sequentially passes through the pupil 2 and the eyepiece optical system 10 from the object side to the display screen 100 for focusing and imaging. In the present embodiment, the aberration expressions shown in the aberration diagrams determine the aberration expressions of the imaging light from the display screen 100 on the retina of the eye of the observer. That is, when the aberrations presented in the aberration diagrams are small, the aberrations of the image of the retina of the eye of the observer are also small, so that the observer can view an image with better imaging quality. Fig. 8A is a diagram illustrating longitudinal spherical aberration (longitudinal spherical aberration) of the first embodiment when the pupil radius (pupil) is 2.5000mm and when the wavelengths are 450nm, 540nm and 630nm, fig. 8B and 8C are diagrams illustrating field curvature (field curvature) aberration and radial curvature aberration on the display 100 with respect to the sagittal direction and radial direction, respectively, of the first embodiment when the wavelengths are 450nm, 540nm and 630nm, and fig. 8D is a diagram illustrating distortion aberration (distortion aberration) on the display 100 when the wavelengths are 450nm, 540nm and 630nm of the first embodiment. In the longitudinal spherical aberration diagram of the first embodiment shown in fig. 8A, the curves formed by each wavelength are very close and close to the middle, which means that the off-axis light beams with different heights of each wavelength are all concentrated near the imaging point, and the deviation of the imaging point of the off-axis light beams with different heights is controlled within the range of ± 1mm as can be seen from the deviation of the curve of each wavelength, so that the present embodiment indeed improves the spherical aberration with the same wavelength, and in addition, the distances between the three representative wavelengths are also very close, which means that the imaging positions of the light beams with different wavelengths are very concentrated, thereby improving the chromatic aberration.

In the two graphs of field curvature aberration of fig. 8B and 8C, the variation of the focal length of the three representative wavelengths in the entire field of view is within ± 5.9 mm, which shows that the optical system of the first embodiment can effectively eliminate the aberration. The distortion aberration diagram of fig. 8D shows that the distortion aberration of the first embodiment is maintained within a range of ± 2.2%, which indicates that the distortion aberration of the first embodiment meets the requirement of the optical system for image quality, and thus the first embodiment can provide good image quality under the condition that the TTL is shortened to about 56.100mm compared with the conventional eyepiece optical system, so that the first embodiment can shorten the length of the optical system and enlarge the visual angle of the eye under the condition that good optical performance is maintained, thereby realizing the product design of miniaturization, low aberration and large visual angle of the eye.

Fig. 11 is a schematic view of an eyepiece optical system according to a second embodiment of the present invention, and fig. 12A to 12D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the second embodiment. Referring to fig. 11, a second embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. In addition, in the present embodiment, the object side surface 31 of the first lens element 3 is a concave surface, and has a concave surface portion 312 located in the vicinity of the optical axis I and a concave surface portion 314 located in the vicinity of the circumference. The second lens element 4 has a negative refractive index. The object side surface 41 of the second lens element 4 is a concave surface, and has a concave surface portion 412 located in the vicinity of the optical axis I and a concave surface portion 414 located in the vicinity of the circumference. The display side surface 42 of the second lens 4 is a flat surface, and has a flat surface portion 425 located in the vicinity of the optical axis I and a flat surface portion 426 located in the vicinity of the circumference. The third lens element 5 has a positive refractive index. In addition, in the present embodiment, the display side surface 52 of the third lens element 5 is a convex surface, and has a convex surface portion 521 located in the vicinity of the optical axis I and a convex surface portion 523 located in the vicinity of the circumference. Note here that, in order to clearly show the drawing, reference numerals of the concave surface portion and the convex surface portion which are the same as those of the first embodiment are omitted in fig. 11. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are spherical surfaces.

Detailed optical data of the eyepiece optical system 10 of the second embodiment is shown in fig. 13, and the entire eyepiece optical system 10 of the second embodiment has an EFL of 44.658mm, ω of 45.000 °, TTL of 57.500mm, Fno of 8.864, and 0.5-fold DLD of 31.563 mm.

As shown in fig. 14, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the second embodiment in formula (1) are shown.

Fig. 43 and 44 show the relationship between important parameters in the eyepiece optical system 10 of the second embodiment.

In the longitudinal spherical aberration diagram of the second embodiment in which the pupil radius is 2.5000mm, in fig. 12A, the deviation of the imaging points of the off-axis rays of different heights is controlled within ± 2 mm. In the two graphs of field curvature aberration of fig. 12B and 12C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 17 mm. The distortion aberration diagram of FIG. 12D shows that the distortion aberration of the second embodiment is maintained within a range of + -30%. Therefore, the second embodiment can provide better imaging quality compared to the conventional eyepiece optical system under the condition that the TTL is shortened to about 57.500 mm.

As can be seen from the above description, the advantages of the second embodiment over the first embodiment are: the Fno of the second embodiment is smaller than that of the first embodiment. ω of the second embodiment is larger than ω of the first embodiment.

Fig. 15 is a schematic view of an eyepiece optical system according to a third embodiment of the present invention, and fig. 16A to 16D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the third embodiment. Referring to fig. 15, a third embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, aspherical coefficients and parameters of these

lenses

3, 4 and 5 are more or less different, and in this embodiment, the object side surface 31 of the first lens 3 has a concave portion 312 in a region where the optical axis I is reduced and a concave portion 314 in a region near the circumference. The eye side surface 41 of the second lens element 4 has a convex surface 411 located in the vicinity of the optical axis I and a concave surface 414 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye-side surface 51 of the third lens element 5 has a convex surface 511 located in the vicinity of the optical axis I and a concave surface 514 located in the vicinity of the circumference. The display side surface 52 of the third lens element 5 has a concave portion 522 located in the vicinity of the optical axis I and a convex portion 523 located in the vicinity of the circumference. Note here that, in fig. 15, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the third embodiment is shown in fig. 17, and the eyepiece optical system 10 of the third embodiment as a whole has an EFL of 48.338mm, ω of 45.000 °, TTL of 53.228mm, Fno of 8.024, and 0.5-fold DLD of 35.333 mm.

As shown in fig. 18, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the third embodiment are shown in formula (1).

Fig. 43 and 44 show the relationship between important parameters in the eyepiece optical system 10 of the third embodiment.

In the longitudinal spherical aberration diagram 16A of the third embodiment in which the pupil radius is 3.0000mm, the deviation of the imaging point of the off-axis ray of different heights is controlled within ± 0.6 mm. In the two graphs of field curvature aberration of fig. 16B and 16C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 1.5 mm. The distortion aberration diagram of FIG. 16D shows that the distortion aberration of the third embodiment is maintained within a range of + -28%. Therefore, the third embodiment can provide better imaging quality under the condition that TTL is shortened to about 53.228mm compared with the conventional optical lens.

As can be seen from the above description, the third embodiment has the following advantages compared to the first embodiment: the eyepiece optical system 10 of the third embodiment has TTL smaller than that of the first embodiment, Fno smaller than that of the first embodiment, and half-eye view angle ω larger than that of the first embodiment. The longitudinal spherical aberration of the third embodiment is smaller than that of the first embodiment. The curvature of field of the third embodiment is smaller than that of the first embodiment.

Fig. 19 is a schematic view of an eyepiece optical system according to a fourth embodiment of the present invention, and fig. 20A to 20D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the fourth embodiment. Referring to fig. 19, a fourth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. In addition, in the present embodiment, the eye side surface 41 of the second lens element 4 has a convex surface 411 located in the vicinity of the optical axis I and a concave surface 414 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 19, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the fourth embodiment is shown in fig. 21, and the eyepiece optical system 10 of the fourth embodiment has an EFL of 49.996mm, ω of 45.000 °, TTL of 61.224mm, Fno of 12.430, and 0.5-fold DLD of 35.638mm as a whole.

As shown in fig. 22, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the fourth embodiment are shown in formula (1).

Fig. 43 and 44 show the relationship between important parameters in the eyepiece optical system 10 of the fourth embodiment.

In the present fourth embodiment, in the longitudinal spherical aberration diagram 20A when the pupil radius is 2.0000mm and when the wavelengths are 486nm, 587nm, and 656nm, the deviation of the imaging points of the off-axis rays of different heights is controlled within ± 0.65 mm. In the two graphs of the field curvature aberrations of FIGS. 20B and 20C at the wavelengths of 486nm, 587nm and 656nm, the variation of the focal length of the three representative wavelengths in the entire field of view is within + -1.1 mm. The distortion aberration diagram of FIG. 20D shows that the distortion aberration of the fourth embodiment is maintained within a range of + -29%. Therefore, the fourth embodiment can provide better imaging quality under the condition that TTL is shortened to about 61.224mm compared with the conventional optical lens.

As can be seen from the above description, the fourth embodiment has the following advantages compared to the first embodiment: ω of the fourth embodiment is larger than ω of the first embodiment. The longitudinal spherical aberration of the fourth embodiment is smaller than that of the first embodiment. The field curvature of the fourth embodiment is smaller than that of the first embodiment. The thickness difference between the optical axis and the area near the circumference of the lens of the fourth embodiment is smaller than that of the first embodiment, so that the fourth embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Fig. 23 is a schematic view of an eyepiece optical system according to a fifth embodiment of the present invention, and fig. 24A to 24D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the fifth embodiment. Referring to fig. 23, a fifth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, aspherical coefficients and parameters of these

lenses

3, 4 and 5 are more or less different, and in this embodiment, the object side surface 41 of the second lens 4 has a convex surface portion 411 located in the vicinity of the optical axis I and a concave surface portion 414 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 23, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the fifth embodiment is shown in fig. 25, and the eyepiece optical system 10 of the fifth embodiment has an overall EFL of 50.117mm, ω of 45.000 °, TTL of 61.318mm, Fno of 12.460, and 0.5-fold DLD of 35.857 mm.

As shown in fig. 26, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 in the formula (1) in the fifth embodiment are shown.

Fig. 43 and 44 show the relationship between important parameters in the eyepiece optical system 10 of the fifth embodiment.

In the longitudinal spherical aberration diagram 24A of the fifth embodiment in which the pupil radius is 2.0000mm, the deviation of the imaging point of the off-axis ray of different heights is controlled within ± 0.62 mm. In the two graphs of field curvature aberration of fig. 24B and 24C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 1.2 mm. The distortion aberration diagram of fig. 24D shows that the distortion aberration of the fifth embodiment is maintained within a range of ± 29%. Therefore, the fifth embodiment can provide better imaging quality under the condition that TTL is shortened to about 61.318mm compared with the conventional optical lens.

As can be seen from the above description, the advantages of the fifth embodiment compared to the first embodiment are: ω of the fifth embodiment is smaller than ω of the first embodiment. The longitudinal spherical aberration of the fifth embodiment is smaller than that of the first embodiment. The field curvature of the fifth embodiment is smaller than that of the first embodiment. The thickness difference between the optical axis and the area near the circumference of the lens of the fifth embodiment is smaller than that of the first embodiment, so that the fifth embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Fig. 27 is a schematic view of an eyepiece optical system according to a sixth embodiment of the present invention, and fig. 28A to 28D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the sixth embodiment. Referring to fig. 27, a sixth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. The display side surface 42 of the second lens element 4 is concave and has a concave portion 422 located in the vicinity of the optical axis I and a concave portion 424 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 27, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the sixth embodiment is shown in fig. 29, and the entire eyepiece optical system 10 of the sixth embodiment has an EFL of 50.272mm, ω of 45.000 °, TTL of 62.697mm, Fno of 8.306, and 0.5-fold DLD of 35.286 mm.

As shown in fig. 30, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the sixth embodiment are shown in formula (1).

Fig. 45 and 46 show relationships between important parameters in the eyepiece optical system 10 of the sixth embodiment.

In the longitudinal spherical aberration diagram 28A of the sixth embodiment in which the pupil radius is 3.0000mm, the deviation of the imaging point of the off-axis ray of different heights is controlled within ± 135 mm. In the two graphs of field curvature aberration of fig. 28B and 28C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 1.2 mm. The distortion aberration diagram of fig. 28D shows that the distortion aberration of the sixth embodiment is maintained within a range of ± 21%. Therefore, the sixth embodiment can provide better imaging quality under the condition that TTL is shortened to about 62.697mm compared with the conventional optical lens.

As can be seen from the above description, the sixth embodiment has the following advantages compared to the first embodiment: the Fno of the sixth embodiment is smaller than that of the first embodiment. ω of the sixth embodiment is smaller than ω of the first embodiment. The curvature of field of the sixth embodiment is smaller than that of the first embodiment. The thickness difference between the optical axis and the area near the circumference of the lens of the sixth embodiment is smaller than that of the first embodiment, so that the sixth embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Fig. 31 is a schematic view of an eyepiece optical system of a seventh embodiment of the present invention, and fig. 32A to 32D are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the seventh embodiment. Referring to fig. 31, a seventh embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. The eye side surface 41 of the second lens element 4 has a convex surface 411 located in the vicinity of the optical axis I and a concave surface 414 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 31, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the seventh embodiment is shown in fig. 33, and the eyepiece optical system 10 of the seventh embodiment has an overall EFL of 50.090mm, ω of 45.000 °, TTL of 63.000mm, Fno of 8.225, and 0.5-fold DLD of 35.192 mm.

As shown in fig. 34, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the seventh embodiment are shown in formula (1).

Fig. 45 and 46 show relationships between important parameters in the eyepiece optical system 10 of the seventh embodiment.

In the longitudinal spherical aberration diagram 32A of the seventh embodiment at a pupil radius of 3.0000mm, the deviation of the imaging point of the off-axis rays of different heights is controlled within ± 1.1 mm. In the two graphs of field curvature aberration of fig. 32B and 32C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 0.9 mm. The distortion aberration diagram of fig. 32D shows that the distortion aberration of the seventh embodiment is maintained within a range of ± 30%. Therefore, compared with the conventional optical lens, the seventh embodiment can still provide good imaging quality under the condition that the TTL is shortened to about 63.000 mm.

As can be seen from the above description, the seventh embodiment has the following advantages compared to the first embodiment: the Fno of the seventh embodiment is smaller than that of the first embodiment. ω of the seventh embodiment is larger than ω of the first embodiment. The field curvature of the seventh embodiment is smaller than that of the first embodiment. The thickness difference between the optical axis and the area near the circumference of the lens of the seventh embodiment is smaller than that of the first embodiment, so that the seventh embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Fig. 35 is a schematic view of an eyepiece optical system according to an eighth embodiment of the present invention, and fig. 36A to 36D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the eighth embodiment. Referring to fig. 35, an eighth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference therebetween is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. In addition, in the present embodiment, the object side surface 31 of the first lens element 3 is a concave surface, and has a concave surface portion 312 located in the vicinity of the optical axis I and a concave surface portion 314 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 35, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the eighth embodiment is shown in fig. 37, and the eyepiece optical system 10 of the eighth embodiment has an EFL of 50.327mm, ω of 45.000 °, TTL of 63.000mm, Fno of 8.092, and 0.5-fold DLD of 34.974mm as a whole.

As shown in fig. 38, the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the eighth embodiment have aspheric coefficients in formula (1).

Fig. 45 and 46 show relationships between important parameters in the eyepiece optical system 10 according to the eighth embodiment.

In the longitudinal spherical aberration diagram 36A of the eighth embodiment, when the pupil radius is 3.0000mm, the deviation of the imaging point of the off-axis ray of different heights is controlled within ± 1.35 mm. In the two graphs of field curvature aberration of fig. 36B and 36C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 0.98 mm. The distortion aberration diagram of fig. 36D shows that the distortion aberration of the eighth embodiment is maintained within a range of ± 30%. Therefore, the eighth embodiment can provide better imaging quality under the condition that TTL is shortened to about 63.000mm compared with the conventional optical lens.

As can be seen from the above description, the eighth embodiment has the following advantages compared to the first embodiment: the Fno of the eighth embodiment is smaller than that of the first embodiment. ω of the eighth embodiment is larger than ω of the first embodiment. The field curvature of the eighth embodiment is smaller than that of the first embodiment. The difference in thickness between the optical axis and the area near the circumference of the lens of the eighth embodiment is smaller than that of the first embodiment, so that the eighth embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Fig. 39 is a schematic view of an eyepiece optical system of a ninth embodiment of the present invention, and fig. 40A to 40D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system of the ninth embodiment. Referring to fig. 39, a ninth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows: the optical data, the aspherical coefficients and the parameters between these

lenses

3, 4 and 5 are more or less different. In addition, in the present embodiment, the eye side surface 31 of the first lens element 3 has a concave surface portion 312 located in the vicinity of the optical axis I and a convex surface portion 313 located in the vicinity of the circumference. The display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I and a convex portion 423 located in the vicinity of the circumference. The eye side surface 51 of the third lens element 5 is a concave surface, and has a concave surface portion 512 located in the vicinity of the optical axis I and a concave surface portion 514 located in the vicinity of the circumference. The display side 52 of the third lens element 5 is a convex surface, and has a convex surface 521 located in the vicinity of the optical axis I and a convex surface 523 located in the vicinity of the circumference. Note here that, in fig. 39, the same reference numerals of the concave surface portion and the convex surface portion as those of the first embodiment are omitted for clarity of illustration. In the present embodiment, the eye side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 are aspheric.

Detailed optical data of the eyepiece optical system 10 of the ninth embodiment is shown in fig. 41, and the eyepiece optical system 10 of the ninth embodiment has an overall EFL of 51.558mm, ω of 45.000 °, TTL of 61.921mm, Fno of 8.324, and 0.5-fold DLD of 35.043 mm.

As shown in fig. 42, the aspheric coefficients of the target side surfaces 31, 41 and 51 and the display side surfaces 32, 42 and 52 of the ninth embodiment are shown in formula (1).

Fig. 45 and 46 show relationships between important parameters in the eyepiece optical system 10 of the ninth embodiment.

In the longitudinal spherical aberration diagram 40A of the ninth embodiment at a pupil radius of 3.0000mm, the deviation of the imaging point of the off-axis rays of different heights is controlled within ± 1.4 mm. In the two graphs of field curvature aberration of fig. 40B and 40C, the variation of focal length of the three representative wavelengths over the entire field of view falls within ± 1.2 mm. The distortion aberration diagram of fig. 40D shows that the distortion aberration of the ninth embodiment is maintained within a range of ± 32%. Therefore, compared with the conventional optical lens, the ninth embodiment can still provide good imaging quality under the condition that the TTL is shortened to about 61.921 mm.

As can be seen from the above description, the ninth embodiment has the following advantages compared to the first embodiment: the Fno of the ninth embodiment is smaller than that of the first embodiment. ω of the ninth embodiment is larger than ω of the first embodiment. The field curvature of the ninth embodiment is smaller than that of the first embodiment. In addition, the thickness difference between the optical axis and the area near the circumference of the lens of the ninth embodiment is smaller than that of the first embodiment, so that the ninth embodiment is easier to manufacture than the first embodiment, and the yield is higher.

Referring to fig. 43 to 46, which are table diagrams of optical parameters of the nine embodiments, when the relationship between the optical parameters in the eyepiece optical system 10 of the embodiment of the present invention satisfies at least one of the following conditional expressions, the design of an eyepiece optical system having good optical performance, effectively shortened overall length, effectively increased eye viewing angle, and being technically feasible can be assisted by the designer:

in order to achieve the effects of shortening the system length of the eyepiece optical system 10 and effectively enlarging the visual angle of the eye, the lens thickness and the air gap between the lenses are appropriately shortened, but considering the difficulty of the lens assembly process and the requirement of taking into account the imaging quality, the lens thickness and the air gap between the lenses need to be mutually matched, so that the eyepiece optical system 10 can achieve a better configuration under the condition that at least one of the following conditional expressions is satisfied:

(a) satisfies 1.0 ≦ TTL/G3D, preferably 1.0 ≦ TTL/G3D ≦ 4.5. When the optical lens satisfies 1.0 ≦ TTL/G3D ≦ 1.5, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 1.5 ≦ TTL/G3D ≦ 4.5, the longitudinal spherical aberration can be improved significantly.

(b) Satisfies 0.5 ≦ (T1+ G12)/T2, preferably 0.50 ≦ (T1+ G12)/T2 ≦ 4.50.

(c) Satisfies 1.5 ≦ TTL/(T1+ T2), preferably 1.50 ≦ TTL/(T1+ T2) ≦ 6.00. When 3.0 ≦ TTL/(T1+ T2) ≦ 6.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When 1.5 ≦ TTL/(T1+ T2) ≦ 3.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(d) Satisfies 2.5 ≦ TTL/(T2+ T3), preferably 2.50 ≦ TTL/(T2+ T3) ≦ 9.00.

(e) Satisfies 3.0 ≦ TTL/(G23+ T3), preferably 3.00 ≦ TTL/(G23+ T3) ≦ 23.00. When the requirements of 6.0 ≦ TTL/(G23+ T3) ≦ 23.0 are satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies that TTL/(G23+ T3) ≦ 3.0, the longitudinal spherical aberration can be improved significantly.

(f) Satisfies 1.0 ≦ D1/T1, preferably 1.00 ≦ D1/T1 ≦ 5.00. When the aberration satisfies 4.0 ≦ D1/T1 ≦ 5.0, the distortion and the astigmatic aberration can be significantly improved. When satisfying 1.0 ≦ D1/T1 ≦ 4.0, a significant improvement in longitudinal spherical aberration can be obtained.

(g) Satisfies 2.0 ≦ D2/T2, preferably 2.00 ≦ D2/T2 ≦ 19.00.

(h) Satisfies 6.0 ≦ D3/T3, preferably 6.00 ≦ D3/T3 ≦ 21.00.

(i) Satisfies T1/T2 ≦ 6, preferably satisfies T1/T2 ≦ 6.00. When 1.4 ≦ T1/T2 ≦ 6.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the composition satisfies 0.5 ≦ T1/T2 ≦ 4.0, a significant improvement in longitudinal spherical aberration can be obtained.

(j) Satisfies 1 ≦ T1/(G12+ T3), preferably 1.00 ≦ T1/(G12+ T3) ≦ 8.00. When 1.0 ≦ T1/(G12+ T3) ≦ 3.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When 3.0 ≦ T1/(G12+ T3) ≦ 8.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(k) Satisfies 0.25 ≦ T2/(G12+ T3), preferably 0.25 ≦ T2/(G12+ T3) ≦ 8.00. When 0.25 ≦ T2/(G12+ T3) ≦ 2.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When 1.4 ≦ T2/(G12+ T3) ≦ 8.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(l) Satisfies G3D/T1 ≦ 7, preferably satisfies 0.5 ≦ G3D/T1 ≦ 7.00. When the relation of 4.0 ≦ G3D/T1 ≦ 7.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 0.5 ≦ G3D/T1 ≦ 1.5, a significant improvement in longitudinal spherical aberration can be obtained.

(m) satisfies G3D/T2 ≦ 22, preferably 0.9 ≦ G3D/T2 ≦ 22.00. When 7.0 ≦ G3D/T2 ≦ 22.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 0.9 ≦ G3D/T2 ≦ 3.0, a significant improvement in longitudinal spherical aberration can be obtained.

(n) satisfies 3 ≦ G3D/T3, preferably 3.0 ≦ G3D/T3 ≦ 18.00. When the relation 5.0 ≦ G3D/T3 ≦ 18.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When 3.0 ≦ G3D/T3 ≦ 8.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(o) satisfies G3D/Gaa ≦ 430, preferably 1.0 ≦ G3D/Gaa ≦ 430.00. When 30.0 ≦ G3D/Gaa ≦ 430.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When satisfying 1.0 ≦ G3D/Gaa ≦ 2.4, a significant improvement in longitudinal spherical aberration can be obtained.

(p) satisfies G3D/ALT ≦ 3.5, preferably 0.4 ≦ G3D/ALT ≦ 3.5. When satisfying 2.00 ≦ G3D/ALT ≦ 3.5, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 0.4 ≦ G3D/ALT ≦ 0.8, a significant improvement in longitudinal spherical aberration can be obtained.

(q) satisfies SL/T1 ≦ 11, preferably 3.0 ≦ SL/T1 ≦ 11.0. When the relation 8.00/SL/T1/11.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When 3.0 ≦ SL/T1 ≦ 6.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

Adjusting the EFL helps to enlarge the viewing angle, and if at least one of the following conditional expressions is satisfied, the adjustment may also help to enlarge the viewing angle when the system length of the eyepiece optical system 10 is shortened:

(a) satisfies 1.0 ≦ EFL/(T1+ G12+ T2), preferably 1.00 ≦ EFL/(T1+ G12+ T2) ≦ 4.50. When 2.0 ≦ EFL/(T1+ G12+ T2) ≦ 4.5 is satisfied, distortion and astigmatic aberration can be significantly improved. When 1.0 ≦ EFL/(T1+ G12+ T2) ≦ 2.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(b) Satisfies 2.0 ≦ EFL/T1, preferably 2.00 ≦ EFL/T1 ≦ 7.00. When EFL/T1 ≦ 7.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the EFL/T1 ≦ 2.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

(c) Satisfies 2.5 ≦ EFL/T2, preferably 2.50 ≦ EFL/T2 ≦ 25.00. When EFL/T2 ≦ 25.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the EFL/T2 ≦ 2.5 ≦ 10.0 is satisfied, a significant improvement in longitudinal spherical aberration can be obtained.

Third, in order to maintain the exit pupil distance ER and the optical parameters at an appropriate value, avoid over-large parameters from adversely affecting the overall thinning of the eyepiece optical system 10, or avoid over-small parameters from adversely affecting the assembly or increasing the difficulty in manufacturing, at least one of the following conditions can be satisfied:

(a) satisfies 0.5 ALT/ER, preferably 0.50 ALT/ER < 3.00. When the value of 0.5 ALT/ER is less than or equal to 1.5, the distortion and astigmatic aberration can be improved significantly. When the value of 1.5 ALT/ER < 3.0 is satisfied, the longitudinal spherical aberration can be improved significantly.

(b) Satisfies 3.5 ≦ TTL/ER, preferably 3.50 ≦ TTL/ER ≦ 5.50. When the optical lens satisfies 3.5 ≦ TTL/ER ≦ 4.5, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 4.5 ≦ TTL/ER ≦ 5.5, a significant improvement in longitudinal spherical aberration can be obtained.

(c) Satisfies 1.1 ≦ G3D/ER, preferably 1.10 ≦ G3D/ER ≦ 3.50. When 2.5 ≦ G3D/ER ≦ 3.5 is satisfied, distortion and astigmatic aberration can be significantly improved. When satisfying 1.1 ≦ G3D/ER ≦ 2.0, a significant improvement in longitudinal spherical aberration can be obtained.

(d) Satisfies ER/T1 ≦ 2.3, preferably 0.50 ≦ ER/T1 ≦ 2.30. When the equation satisfies 1.5 ≦ ER/T1 ≦ 2.3, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 0.5 ≦ ER/T1 ≦ 1.2, the longitudinal spherical aberration can be significantly improved.

(e) Satisfies ER/T2 ≦ 8, preferably 0.60 ≦ ER/T2 ≦ 8.00. When 2.5 ≦ ER/T2 ≦ 8.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 0.6 ≦ ER/T2 ≦ 2.5, the longitudinal spherical aberration can be significantly improved.

(f) Satisfies 2 ≦ ER/T3, preferably 2.00 ≦ ER/T3 ≦ 7.00. When 2.0 ≦ ER/T3 ≦ 6.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 2.5 ≦ ER/T3 ≦ 5.0, the longitudinal spherical aberration can be significantly improved.

(g) Satisfies EFL/ER < 4.5, preferably 2.00 < EFL/ER < 4.50. When the EFL/ER ratio is less than or equal to 3.5 and less than or equal to 4.5, the longitudinal spherical aberration can be improved remarkably.

Fourthly, by limiting the magnitude relation between the EPSD and each optical parameter, the half-eye visual angle is not too small to cause visual stenosis:

(a) satisfies DLD/EPSD ≦ 36, preferably satisfies 20.0 ≦ DLD/EPSD ≦ 36.00. When DLD/EPSD ≦ 28.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the DLD/EPSD ≦ 36.0 is satisfied, the longitudinal spherical aberration can be improved significantly. In addition, when 6 ≦ 0.5DLD/EPSD ≦ 20 is satisfied, aberration can be significantly improved.

(b) Satisfies DLD/G3D ≦ 5, preferably 1.30 ≦ DLD/G3D ≦ 5.00. When 1.3 ≦ DLD/G3D ≦ 2.2 is satisfied, distortion and astigmatic aberration can be significantly improved. When DLD/G3D ≦ 5.0 is satisfied, the longitudinal spherical aberration can be significantly improved.

(c) EFL/DLD is satisfied at 0.8, preferably EFL/DLD is satisfied at 0.6 at 0.80. When the EFL/DLD is less than or equal to 0.65 and less than or equal to 0.75, the longitudinal spherical aberration can be improved remarkably.

When the eyepiece optical system 10 satisfies the condition of f2/f1 ≦ 15, it is advantageous that the second lens element 4 does not affect the EFL or the image magnification of the eyepiece optical system 10 too much under the condition of correcting the aberration of the first lens element 3, and preferably satisfies the condition of (-3) ≦ f2/f1 ≦ 15, so as to avoid that the refractive index of the second lens element 4 is too small to correct the aberration of the first lens element 3. When (-3.0) ≦ f2/f1 ≦ 3.0 is satisfied, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 3.0 ≦ f2/f1 ≦ 15.0, a significant improvement in longitudinal spherical aberration can be obtained.

Six and 250mm are the photopic distance of young people, i.e. the nearest distance that the eyes of young people can focus clearly, the magnification of the system can be approximate to the ratio of 250 millimeters (mm) to G3D, so that when the system satisfies 250mm/G3D ≦ 25, the magnification of the system is not too large, which increases the thickness of the lens and the difficulty of manufacturing. Further, if 2.5 ≦ 250mm/G3D ≦ 25 is satisfied, the length of the imaging system is not too long for G3D. When the aberration satisfies 2.5 ≦ 250mm/G3D ≦ 10.0, distortion and astigmatic aberration can be significantly improved. When the formula satisfies 10.0 ≦ 250mm/G3D ≦ 25.0, a significant improvement in longitudinal spherical aberration can be obtained.

Seventh, under the condition of satisfying at least one of the following conditional expressions, the definition of the local imaging of the object can be effectively enhanced, and the aberration of the local imaging of the object can be effectively corrected:

(a) satisfies ν 1/ν 2 of 0.8 or less, preferably satisfies ν 1/ν 2 of 0.80 or less and 3.0 or less. When the value of v 1/v 2 is 0.8 ≦ 1.2, the longitudinal spherical aberration can be improved significantly.

(b) With the second embodiment, when both of | v 1-v 2 | 20 and | v 1-v 3 | ≦ 5 are satisfied, aberration for partial imaging of the object can be effectively corrected. In other embodiments, when both of | v 1-v 2 | ≦ 5 and | v 1-v 3 | ≧ 20 are satisfied, aberration for partial imaging of the object can be effectively corrected.

Eighthly, when the system satisfies 40 DEG ≦ omega, the observer can feel more immersive.

Ninthly, if the system can satisfy at least one of the following conditional expressions: 0.69 ≦ (ER + G + T)/T ≦ 2.09, 0.79 ≦ (ER + G + T)/T ≦ 3.25, 0.99 ≦ (ER + G + T)/G ≦ 16.16, 0.38 ≦ (ER + G + T)/G3 ≦ 1.02, 1.27 ≦ (ER + G + G3)/T ≦ 7.19, 1.71 ≦ (ER + G + G3)/T ≦ 11.19, 1.81 ≦ (ER + G + G3)/Gaa ≦ 49.2, 1.03 ≦ (ER + T + T)/T ≦ 2.72, 0.49 ≦ (ER + T + T)/G3 ≦ 1.71, 1.84 ≦ ER + T + G3)/T11.72, 0.7 ≦ (ER + G + T)/T ≦ 3, 0.43 ≦ G + T3/G3, or a distance between the eye pupil and the ER + T < 3/G + T < 23.82, or between the eye parameter and the eye is not larger than the E < 7/T < 3/T < 7/T < 3/E + T < 7/E + T < 3/E + E < 3, either to avoid the influence of too small any parameter on the assembly or to increase the difficulty of manufacturing.

If the system can satisfy at least one of the following conditional expressions: 1.06 ≦ (ER + G12+ T3)/T1 ≦ 2.77, 0.79 ≦ (ER + G12+ T3)/T2 ≦ 11.05, 1.63 ≦ (ER + G12+ T12)/G12 ≦ 55.25, 0.38 ≦ (ER + G12+ T12)/G3 12 ≦ 0.83, 2.08 ≦ (ER + G12+ G3 12)/T12 ≦ 7.19, 1.71 ≦ (ER + G12+ G3 12)/T12 ≦ 27.55, 3.49 ≦ (ER + G12+ G3 12)/Gaa ≦ 110.2, 2.1 ≦ (ER + T12 + T12)/T12 ≦ 3, 1.84 ≦ (ER + G12+ G3)/G12 ≦ 7.7.7, 3.7.7.7 ≦ 7.7 ≦ 7 + G + T12)/G + E3, 3.3 ≦ 7.3 ≦ 7 + G + E + 7 + E3, 3 ≦ 7.7 + E.

Eleven if the system can satisfy at least one of the following conditional expressions: 2.08 ≦ (ER + G + T)/T ≦ 2.77, 3.24 ≦ (ER + G + T)/T ≦ 11.05, 16.15 ≦ (ER + G + T)/G ≦ 55.25, 0.38 ≦ (ER + G + T)/G3 ≦ 0.56, 6.88 ≦ (ER + G + G3)/T ≦ 7.19, 11.18 ≦ (ER + G + G3)/T ≦ 27.55, 49.19 ≦ (ER + G + G3)/Gaa ≦ 110.2, 2.71 ≦ (ER + T + T)/T ≦ 3, 0.49 ≦ (ER + T + T)/G3 ≦ 0.6, 11.71 ≦ (ER + T + G3)/T31, 0.7 ≦ (ER + G + T)/T ≦ 3, 0.43 ≦ G + T ≦ 3 ≦ 0.82/G + T3, and the longitudinal gap spacing between (ER + G + T)/G + T3 ≦ 0.82/E + G + T ≦ 0.82/E + T/E + G + E.

Twelve, if the system can satisfy at least one of the following conditional expressions: TTL/EFL ≦ 1.1 ≦ TTL/EFL ≦ 1.29, SL/EFL ≦ 1.34 ≦ 1.63, DLD/EFL ≦ 1.35, and DLD/EFL ≦ 1.2 ≦ (T1+ G23)/T2 ≦ 6.06, it is possible to maintain an appropriate value for each parameter of EFL or optics, and avoid that any parameter is too large to facilitate correction of aberration of the eyepiece optical system 10 as a whole, or that any parameter affects assembly or increases difficulty in manufacturing. When at least one of TTL/EFL ≦ 1.29, SL/EFL ≦ 1.43 ≦ 1.63, DLD/EFL ≦ 1.47, and DLD/EFL ≦ 1.2 ≦ T1+ G23/T2 ≦ 4.2 is satisfied, it is advantageous to reduce the field curvature. When 1.75 ≦ (T1+ G23)/T2 ≦ 4.2 is satisfied, it is advantageous to reduce longitudinal spherical aberration.

However, in view of the unpredictability of the optical system design, meeting the above conditions under the architecture of the embodiment of the present invention can preferably make the system length of the embodiment of the present invention shorter, the available aperture larger, the eye viewing angle increased, ER >8mm, the imaging quality improved, or the assembly yield improved to improve the drawbacks of the prior art.

In summary, the eyepiece optical system 10 of the embodiment of the invention can achieve the following effects and advantages:

first, the longitudinal spherical aberration, the field curvature and the distortion of each embodiment of the invention all meet the use specification. In addition, the off-axis light beams with the wavelengths of 450nm, 540nm and 630nm, or 486nm, 587nm and 656nm are all concentrated near the imaging point, and the deviation of the imaging point of the off-axis light beams with different heights can be controlled by the deflection amplitude of each curve, so that the off-axis light beam has good spherical aberration, aberration and distortion inhibition capability. Further referring to the imaging quality data, the distances between the three representative wavelengths of 450nm, 540nm and 630nm, or 486nm, 587nm and 656nm are also very close, which shows that the embodiments of the present invention have excellent concentration to different wavelengths of light and excellent dispersion suppression capability in various states, and thus it can be seen that the embodiments of the present invention have good optical performance.

The second lens element 3 has a positive refractive index, the display side surface 42 of the second lens element 4 has a convex surface 421 located in the vicinity of the optical axis I, the eye side surface 51 of the third lens element 5 has a convex surface 511 located in the vicinity of the optical axis I, and the eye side surface 41 of the second lens element 4 has a convex surface 411 located in the vicinity of the optical axis I or the eye side surface 41 of the second lens element 4 has a convex surface 413 located in the vicinity of the circumference, which is favorable for reducing curvature of field. Alternatively, the curved field can be reduced by selecting the shape characteristics that the display side surface 42 of the second lens element 4 has the convex surface 421 located in the vicinity of the optical axis I, the eye side surface 51 of the third lens element 5 has the convex surface 511 located in the vicinity of the circumference and the convex surface 513 located in the vicinity of the circumference, and the third lens element 5 has the negative refractive index, and the display side surface 52 of the third lens element 5 has the concave surface 522 located in the vicinity of the optical axis I or the display side surface 52 of the third lens element 5 has the concave surface 524 located in the vicinity of the circumference. The distortion is advantageously reduced by the configuration that the eye-side surface 41 of the second lens element 4 has the convex surface 411 located in the vicinity of the optical axis I, the eye-side surface 51 of the third lens element 5 has the convex surface 511 located in the vicinity of the optical axis I, the display-side surface 52 of the third lens element 5 has the concave surface 524 located in the vicinity of the circumference, and the second lens element 4 has the positive refractive index, the display-side surface 42 of the second lens element 4 has the convex surface 421 located in the vicinity of the optical axis I, the display-side surface 42 of the second lens element 4 has the convex surface 423 located in the vicinity of the circumference, or the third lens element 5 has the negative refractive index.

Third, the object side surface 31 of the first lens element 3 has a concave portion 312 located in the vicinity of the optical axis I, and the display side surface 52 of the third lens element 5 has a convex portion 523 located in the vicinity of the circumference, which is favorable for reducing curvature of field. The concave portion 312 located in the vicinity of the optical axis I on the eye-side surface 31 of the first lens element 3, and the concave portion 414 located in the vicinity of the circumference on the eye-side surface 41 of the second lens element 4 or the convex portion 511 located in the vicinity of the optical axis I on the eye-side surface 51 of the third lens element 5 are used together, which is advantageous for reducing the longitudinal spherical aberration. The eye side surface 31 of the first lens element 3 has a concave portion 312 located in the vicinity of the optical axis I, the eye side surface 31 of the first lens element 3 has a convex portion 313 located in the vicinity of the circumference, the second lens element 4 has a negative refractive index, the eye side surface 41 of the second lens element 4 has a concave portion 412 located in the vicinity of the optical axis I, the third lens element 5 has a positive refractive index, or the eye side surface 51 of the third lens element 5 has a convex portion 513 located in the vicinity of the circumference, which is beneficial for imaging light entering the eye.

Fourth, the display side surface 42 of the second lens element 4 has a concave portion 422 located in the vicinity of the optical axis I, and the second lens element 4 has a positive refractive index, which is favorable for reducing distortion. The display side surface 42 of the second lens element 4 has the concave portion 422 located in the area near the optical axis I, and the eye side surface 41 of the second lens element 4 has the convex portion 411 located in the area near the optical axis I, and the third lens element 5 has the negative refractive index, or the eye side surface 51 of the third lens element 5 has the concave portion 514 located in the area near the circumference, which is favorable for reducing the longitudinal spherical aberration. The field curvature can be advantageously reduced by providing the eye-side surface 41 of the second lens element 4 with a convex surface portion 411 located in the vicinity of the optical axis I, the display-side surface 42 of the second lens element 4 with a concave surface portion 422 located in the vicinity of the optical axis I, and the eye-side surface 41 of the third lens element 5 with a concave surface portion 512 located in the vicinity of the optical axis I, or by providing the eye-side surface 41 of the second lens element 4 with a convex surface portion 411 located in the vicinity of the optical axis I, the eye-side surface 51 of the third lens element 5 with a concave surface portion 512 located in the vicinity of the optical axis I, and the display-side surface 52 of the third lens element 5 with a convex surface portion 521 located in the vicinity of the.

Furthermore, any combination relationship of the parameters of the embodiment can be selected to increase the system constraint, so as to facilitate the system design with the same architecture of the embodiment of the present invention. In view of the unpredictability of the optical system design, meeting the above conditions under the architecture of the embodiments of the present invention can preferably enable the system length of the embodiments of the present invention to be shortened, the exit pupil diameter to be increased, the imaging quality to be improved, or the assembly yield to be improved, thereby improving the disadvantages of the prior art.

Sixthly, the exemplary limiting relations listed above may be arbitrarily and selectively combined in different numbers to be applied to the embodiments of the present invention, and are not limited thereto. In addition to the above relations, the present invention may also be implemented with additional features such as concave-convex curved surface arrangement of other lenses for a single lens or a plurality of lenses to enhance the control of the system performance and/or resolution, for example, a convex surface located in the vicinity of the optical axis may be optionally formed on the object side surface of the first lens. It should be noted that these details need not be selectively incorporated into other embodiments of the present invention without conflict.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the first lens element has positive refractive index;

the eye side surface of the third lens is provided with a concave surface part located in an area near the optical axis, and the eye side surface of the third lens is provided with a concave surface part located in an area near the circumference;

the eyepiece optical system conforms to: 2.50 ≦ ER/T3 ≦ 5.00, and 0.8 ≦ v 1/v 2 ≦ 1.2, where ER is the distance of the pupil of the eye of the observer to the first lens on the optical axis, T3 is the thickness of the third lens on the optical axis, v1 is the abbe number of the first lens, and v 2 is the abbe number of the second lens;

the eyepiece optical system has only the above 3 lenses with refractive index.

2. The eyepiece optics system of claim 1, wherein the eyepiece optics system conforms to: 1.50 ≦ TTL/(T1+ T2) ≦ 6.00, where TTL is a distance between the eye-side surface of the first lens and the display screen on the optical axis, T1 is a thickness of the first lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

3. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the eyepiece optical system conforms to: 0.60 ≦ ER/T2 ≦ 2.50, 2.50 ≦ EFL/T2 ≦ 10.00, and 0.8 ≦ v 1/v 2 ≦ 1.2, where ER is a distance of a pupil of the eye of the observer to the first lens on the optical axis, T2 is a thickness of the second lens on the optical axis, EFL is a system focal length of the eyepiece optical system, v1 is an abbe number of the first lens, and v 2 is an abbe number of the second lens;

the eyepiece optical system has only the above 3 lenses with refractive index.

4. The eyepiece optics system of claim 3, wherein the eyepiece optics system conforms to: 1.00 ≦ EFL/(T1+ G12+ T2) ≦ 2.00, where T1 is a thickness of the first lens on the optical axis, and G12 is an air gap from the first lens to the second lens on the optical axis.

5. The eyepiece optical system of claim 1 or 3, wherein the eyepiece optical system conforms to: 1.50 ≦ TTL/G3D, where TTL is a distance on the optical axis from the eye side of the first lens to the display screen, and G3D is a distance on the optical axis from the third lens to the display screen.

6. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the eyepiece optical system conforms to: 0.60 ≦ ER/T2 ≦ 2.50, and 2.50 ≦ TTL/(T2+ T3), where ER is a distance of a pupil of the eye of the observer to the first lens on the optical axis, T2 is a thickness of the second lens on the optical axis, TTL is a distance of the eye-side surface of the first lens to the display screen on the optical axis, and T3 is a thickness of the third lens on the optical axis;

the eyepiece optical system has only the above 3 lenses with refractive index.

7. The eyepiece optics system of claim 6, wherein the eyepiece optics system conforms to: 3.00 ≦ G3D/T3 ≦ 8.00, where G3D is a distance between the third lens and the display screen on the optical axis.

8. The eyepiece optics system of claim 3 or 6, wherein the eyepiece optics system conforms to: 0.50 ≦ (T1+ G12)/T2 ≦ 4.50, where T1 is the thickness of the first lens on the optical axis, and G12 is the air gap from the first lens to the second lens on the optical axis.

9. The eyepiece optics system of claim 3 or 6, wherein the eyepiece optics system conforms to: 0.50 ≦ T1/T2 ≦ 4.50, where T1 is the thickness of the first lens on the optical axis.

10. The eyepiece optics system of claim 3 or 6, wherein the eyepiece optics system conforms to: 0.90 ≦ G3D/T2 ≦ 3.00, wherein G3D is a distance between the third lens and the display screen on the optical axis.

11. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the eyepiece optical system conforms to: 1.40 ≦ T2/(G12+ T3) ≦ 8.00, and 2.50 ≦ TTL/(T2+ T3) ≦ 9.00, where T2 is a thickness of the second lens on the optical axis, G12 is an air gap between the first lens and the second lens on the optical axis, T3 is a thickness of the third lens on the optical axis, and TTL is a distance between the eye-side surface of the first lens and the display screen on the optical axis;

the eyepiece optical system has only the above 3 lenses with refractive index.

12. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the eyepiece optical system conforms to: ω ≧ 40 °, 2.50 ≦ TTL/(T2+ T3), and 0.25 ≦ T2/(G12+ T3), wherein ω is a half-eye viewing angle, TTL is a distance on the optical axis from the eye-side surface of the first lens to the display screen, T2 is a thickness on the optical axis of the second lens, T3 is a thickness on the optical axis of the third lens, and G12 is an air gap on the optical axis from the first lens to the second lens;

the eyepiece optical system has only the above 3 lenses with refractive index.

13. The eyepiece optics system of claim 11 or 12, wherein the eyepiece optics system conforms to: 1.50 ≦ TTL/G3D, where G3D is the distance between the third lens and the display screen on the optical axis.

14. An eyepiece optical system is used for imaging light entering eyes of an observer from a display picture through the eyepiece optical system, the direction facing the eyes is an eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, and the first lens, the second lens and the third lens respectively comprise an eye side surface and a display side surface;

the eyepiece optical system conforms to: 3.00 ≦ G3D/T3, 2.50 ≦ TTL/(T2+ T3), 0.25 ≦ T2/(G12+ T3), and 1.34 ≦ SL/EFL ≦ 1.63, where G3D is a distance from the third lens to the display screen on the optical axis, T3 is a thickness of the third lens on the optical axis, TTL is a distance from the eye-side surface of the first lens to the display screen on the optical axis, T2 is a thickness of the second lens on the optical axis, G12 is an air gap from the first lens to the second lens on the optical axis, SL is a system length, i.e., a distance from the pupil of an observer to the display screen on the optical axis, and EFL is a system focal length of the eyepiece optical system;

the eyepiece optical system has only the above 3 lenses with refractive index.

15. The eyepiece optics system of claim 14, wherein the eyepiece optics system conforms to: 2.5 ≦ 250/G3D ≦ 25.

16. The eyepiece optics system of claim 11, 12 or 14, wherein the eyepiece optics system conforms to: 1.50 ≦ TTL/(T1+ T2) ≦ 6.00, where T1 is the thickness of the first lens on the optical axis.

17. The eyepiece optics system of claim 11, 12 or 14, wherein the eyepiece optics system conforms to: 0.60 ≦ ER/T2 ≦ 2.50, where ER is the distance of the pupil of the eye of the observer to the first lens on the optical axis.

18. The eyepiece optics system of claim 11, 12 or 14, wherein the eyepiece optics system conforms to: 2.50 ≦ ER/T3 ≦ 5.00, where ER is the distance of the pupil of the eye of the observer to the first lens on the optical axis.

19. The eyepiece optics system of claim 11, 12 or 14, wherein the eyepiece optics system conforms to: 22.00 ≦ DLD/EPSD ≦ 36.00, where DLD is the diagonal length of the display corresponding to a single pupil of the observer and EPSD is the half diameter of the pupil of the observer.

20. The eyepiece optics system of claim 11, 12 or 14, wherein the eyepiece optics system conforms to: v 1/v 2 ≦ 0.8, wherein v1 is the abbe number of the first lens and v 2 is the abbe number of the second lens.